As W W Gill (Manx Scrapbook vol 1 chapter 3) states: "In the Isle of Man bridges are a comparatively modern convenience" - without a system of adequate roads most transport was either by sea or by pack horses - the latter could usually negotiate the fords across the Island rivers which are generally fairly small - for pedestrians there were usually stepping stones though both of these could be impassable when the river was in spate. Speed's map of 1595 shows only two bridges - the Crossag bridge across the Siverburn at Ballasalla and a bridge at Douglas - illustrated by Daniel King c. 1648 which appears to be a simple plank bridge.
Earl Charles issued the following decree [in Lib Canc 1666 p 51]:
Whereas I am given to understand that sever=
=all persons doe perish, & alsoe that Mar=
=kets & Churchwayes are much obstructed
for want of good bridges in my Isle of
Mann I doe therefore order that my
Governor & Officers there doe forthwch meete
consider & sett downe a generall assessment
upon all persons inhabiting wthin my
said Isle (according to their abilities or
houldings) and the same to be collected
and bridges to be therewth built (or rebuilt)
in such places, & after such maner as my
sd officers shall in their discretion think
fitt. Given under my hand at Knows
=ley the 18th day of June 1666
Capt Greenville Collins produced a maritime chart of the Island as part of an extensive servey of the English coast - he noted that he surveyed Liverpool, Isle of Man, Carrackfergus etc in summer 1687 - the map appeared as sheet 31 in Great Britain's Coasting Pilot in 1693 - though a maritime chart it shows some inland detail possibly based on a brief survey - it shows bridges at:
Castletown - directly east of Castle Rushen
Douglas - downstream of the Nunnery near to where the river bends north
Peel - a bridge across the Neb somewhat downstream of Peel, probably the Glenfaba bridge
The Douglas bridge is discussed by by Michael Hoy where he makes an extremely strong case that this was a four arch low parapet bridge for which a considerable part of the cost was bourne by Bishop Barrow (Bishop and Governor 1663-1670) - the 1868 O/S plan XIII 12.6 shows a ruined bulwark on the north side (and possibly on the south bank) opposite Grove View cottages, situated just before the river turns to the north - a 1758 plan by the Douglas Harbour Commissioners shows a 4 arch bridge at about the same point.
The Castletown bridge is not shown in Daniel King's drawings of the 1640's - these were the basis of engravings in Chaloner's A Short Treatise of the Isle of Man published as an appendix to The Vale Royal in 1656 - Earl James as part of the defence of Castletown had constructed the 'new works' at the river side near to the castle gate - this was a platform on the west bank at about the narrowest part of the river channel which would form a good basis for a future bridge - Eva Wilson has some discussion of this and later bridges across the Silverburn in Castown A Miscellany - Hoy suggests it might date from around 1649 based on a note by Archdeacon Rutter that he had 6s commutation money (a sum paid to avoid ecclesiatical penance) to pay towards the Castletown bridge, another commutation in 1650 saw 4s towards the Castle bridge.
A petition of 1728 (entered in Lib Scacc) is from inhabitants of the Northside relating "the great inconveniency and hardships " of "particularly the tennants of the parish of KK Bride, K K Andrews, Jurby, Ballaugh and most of the tennants of KK Christ Leysayre beside the town of Ramsey and KK Maughold " labour under for want of a convenient bridge - delays and unnecessary journies caused by the greatness of fludds and sometimes of Spring tides - signed by most merchants of Ramsey and others from the parishes.
Another petition of 1728 was from inhabitants of Douglas to erect a bridge over the Bright River (river Glas) between Douglas and Kk Braddan Church as 'the said river is very dangerous at severall times in the year, but more especially in the winter when the floods are continually high" - John Carras a mason of Douglas is named as one who build a stone bridge if sufficient money was forthcoming. This is presumeably today's Quarterbridge.
Waldron describing the situation around 1725 states there were 9 major bridges
(1) Castle-Town bridge. This is built of stone, kept in good repair, is of a handsome breadth, and so high, that a boat
with a mast may sail under it.
(2) Ballasalli bridge. This is the oldest bridge in the Island, and built also of stone.
(3) Kirk-Braddon bridge. This is a strait stone bridge; a fine river runs under it, called the Dark river. Here is great plenty of fish, especially eels. - this is presumeably that at Kk Braddan Church
(4) Duglas bridge. This is lately broken down by the rapidity of the river. A woman who was going over it, with a bottle of brandy in her hand, just when the accident happened, was saved by the stiffness of her hoop petticoat which kept her above water.
(5) Nunnery bridge. This bridge has a stone foundation, but is boarded over, and rail'd in, by reason of the turbulence of the river, which sometimes threatens to overflow it. Here they bring their leather to soak.
(6) Laxey bridge. This is the most beautiful of any in the Island, has handsome seats to sit on, and is built over a fine river, which runs between two great hills.
(7) Peel bridge. Under this is the most famous river in the Island; it comes from Kirk Jarmyn mountains, and runs into the sea by the great rock on which stands Peel castle - ? is this GlenFaba bridge
(8) The Millaroats his Mill bridge. This is a small bridge, but built of stone, and much frequented.
(9) Kirk Maroan bridge. A fine river, coming from Kirk Maroan mountains, runs under this bridge to Kirk Santon - this is presumeably that at Mwyllin-e-Quinney on the old Castletown road.
There are, besides these, several small bridges, but not the twentieth part sufficient for the convenience of the inhabitants; yet, notwithstanding a proposal was made for building as many as were wanted, on every housekeeper's paying the sum of one penny per year for nine years, it was not complied with.
There were several Acts of Tynwald from early 18th century authorising the construction (or rebuilding) of bridges and
also instituting a tax basis to fund this and future maintenance - the first of these, that of 1739,
introduced a poll tax of 1d per head per year for 14 years (& extended in 1753
for another 21 years) and required the construction of 5 bridges:
(1) Sulby Bridge on the Ramsey road;
(2) a bridge " over that River called the Great River, between St. John's Chappell and Peeltown "-i.e., at Ballaleece over the Neb;
(3) Ballalonna Bridge, on the boundary between Santon and Malew ; - this the bridge on the New Castletown road across Santan Burn
(4) the bridge at the top of Ramsey Harbour; and
(5) Glen Faba Bridge, on the boundary between German and Patrick.
Later acts moved the tax base to that raised by licences to sell Ale and Spirits and a tax on Dogs - bridges coming then under the various highway commissions.
Early Bridges described by Waldron, 1726. In Manx Soc. xi, 58-9, 133.
Ancient Roads and Bridges. In Oswald's Vestigia. Manx Soc. v. 100-2. 1860.
Highways and Bridges : Acts relating thereto. In Sir James Gell's Abstract of Laws. Manx Soc. xii, 237-9.
Highways and Bridges. In A. W, M. Hist. pp. 446-8; 632-6; 722-3.
Michael Hoy Bishop Barrow's Bridge The Antiquarian No 7 (Autumn 2012) pp19/34
Eva Wilson Castletown A Miscellany Castletown Heritage Occasional Papers No 3  ISBN 978-0-9545413-3-0